Nice work, I love exploiting unicode characters to "draw" in terminal environments. You seem to use '╰', '╮', '╭' and '╯' to approximate non-straight lines, interesting idea, I haven't seen this before.
Another approach is to use block characters, like U+259A or U+259E (see https://en.wikipedia.org/wiki/Block_Elements), but unfortunately it is hard to do when you want to support colors as it doesn't go well with intersections.
//edit: HN does not like block elements, but your 21th century terminal will print them
No? Even this very Wikipedia article says CP866 inherited the box-drawing characters from CP437 (and I bet that wasn't the first character set that had them).
Cool little project, I would put the gif of the graph at the beginning of the Readme before the advanced example. This shows off the application a bit earlier.
I'm trying to make a trading bot but shifting through over a milion of historical prices tends to be a bit uncomfortable when they are outputted in a simple table.
So i looked for some chart that could help me visualize it but found none written in php so I wrote one myself.
Another approach is to use block characters, like U+259A or U+259E (see https://en.wikipedia.org/wiki/Block_Elements), but unfortunately it is hard to do when you want to support colors as it doesn't go well with intersections.
//edit: HN does not like block elements, but your 21th century terminal will print them